Definition
Slipped upper femoral epiphysis (SUFE/SCFE) is displacement through the proximal femoral physis during adolescence. The metaphysis moves anteriorly and externally relative to the epiphysis, which remains seated in the acetabulum.
Risk factors
- adolescent growth spurt
- obesity
- proximal femoral/physeal geometry
- endocrine or metabolic disorders in atypical presentations
- renal osteodystrophy
- previous radiation
Consider endocrine investigation when the child is unusually young, has low body weight/short stature, or the presentation is otherwise atypical.
Presentation
- groin, thigh or referred knee pain
- limp
- reduced hip internal rotation
- obligate external rotation during flexion
A child with persistent knee pain and limp must have the hip examined.
Stability
The clinically important Loder distinction is:
- stable: child can bear weight, with or without aids
- unstable: unable to bear weight even with aids
Unstable slips have a much higher risk of avascular necrosis.
Imaging
Obtain AP pelvis and lateral imaging of both hips when safe. Findings include:
- physeal widening/irregularity
- reduced epiphyseal height
- failure of Klein's line to intersect the epiphysis in more obvious slips
Do not force a frog-leg lateral in an unstable painful slip.
AP pelvis and lateral imaging are used. In a stable suspected slip, frog-lateral views can demonstrate displacement, but forceful positioning should be avoided in an unstable painful hip.
Radiographic signs include widening/irregularity of the physis and failure of a line along the superior femoral neck to intersect the epiphysis appropriately.
Treatment
The immediate aim is to prevent further slip while preserving blood supply.
For most stable slips, in-situ single-screw fixation is standard.
Severe deformity may later require corrective surgery. Open realignment at the physis is a specialist procedure because of the risk to femoral-head blood supply.
Contralateral hip
Prophylactic fixation is individualized. Consider age, skeletal maturity, endocrine disease, ability to attend follow-up and contralateral radiographic risk factors.
The risk of a later contralateral slip is clinically significant. Prophylactic fixation is considered in selected high-risk patients, including those with endocrine disease or other strong risk factors.
Complications
avascular necrosis
chondrolysis
residual cam deformity and femoroacetabular impingement
early osteoarthritis
avascular necrosis
chondrolysis
femoroacetabular impingement
residual deformity
leg-length difference
early osteoarthritis
contralateral slip
Definition and epidemiology
Slipped upper femoral epiphysis is displacement through the proximal femoral physis, with the metaphysis moving anterosuperiorly relative to the epiphysis. It usually occurs around puberty and is associated with obesity and endocrine disorders in some patients.
Always think about an endocrine cause in:
- unusually young children
- low body weight
- bilateral disease
- atypical presentation
Clinical presentation
Pain may be felt in:
- groin
- thigh
- knee
Knee pain can delay diagnosis.
Examination typically shows:
- reduced internal rotation
- obligate external rotation during hip flexion
- limited flexion
- antalgic gait
- out-toeing
Both hips should be assessed.
Stable versus unstable
Clinical stability is important.
A stable slip is one in which the child can weight bear, with or without aids. An unstable slip cannot weight bear even with support.
Unstable slips have a substantially higher risk of avascular necrosis.
Immediate management
Once suspected:
- stop weight bearing
- avoid repeated manipulation
- arrange urgent orthopaedic management
The standard goal is to prevent further slip.
In-situ fixation
Stable slips are commonly treated with in-situ screw fixation. The aim is secure epiphyseal fixation without attempting forceful reduction.
Important technical points include:
- guidewire position
- screw centred within the epiphysis
- adequate thread purchase
- avoidance of joint penetration
Unstable slip
Management is more controversial because restoring alignment may improve anatomy but manipulation can compromise the blood supply. Treatment should be undertaken by an experienced paediatric hip team with careful attention to timing, reduction strategy and capsular pressure where relevant.
FRCS synthesis
The key station points are recognise knee pain as possible hip disease, stop weight bearing, classify stability, and stabilise the physis without forceful manipulation of a stable slip.